Vertically operating hydraulic packers have long been used in tobacco redrying factories to pack the redried tobacco into cases or bales. In usual form, such packers comprise a compression chamber which communicates at its top with an elongated hollow upright charger, a vertically acting press ram having a press head being aligned above the charger so that the ram can be operated to force the press head downwardly through the charger to or into the compression chamber. With the press head raised, the loose tobacco to be packed is supplied into the top of the charger below the press head, with supply continuing until the charger contains a predetermined quantity of loose uncompacted tobacco, and the ram is then operated to force the press head downwardly through the charger and compress the entire quantity of tobacco into the compression chamber. While such packers have achieved great success, problems have arisen because of continually increasing production capabilities of the redrying factories. Tobacco redryers are operated continuously and, in usual cases, one packer must handle the entire output of the redryer and must do so without delays or interruptions, else the entire redrying line must be shut down. Accordingly, as production rates at the redryer factories increased, the rate of fill of tobacco into the charger of the packer increased, and it has been necessary to make the chargers taller and taller until the height of the chargers is now as much as twenty four feet or more. Since the press ram necessarily includes a rectilinear hydraulic motor of the piston and cylinder type, with the cylinder extending vertically above the charger for a distance determined by the length of the stroke of the press head through the charger, the total height of the packer has become quite great. Thus, in a typical packer having a charger seventeen feet tall, total height of the packer may be sixty six feet. Such heights frequently pose severe problems. In some cases, it is necessary that the packer extend upwardly through the roof of the building in which the redryer is housed. In the case of multistory buildings, there is frequently no suitable location for a very tall packer. Increasing the height of the packer increases he cost, both of the packer and of the conveyor system which supplies tobacco to the charger, and also makes the conveyor systems unduly complicated. Increasing the charger height also exascerbates another problem encountered with such packers. A rapid down stroke of the ram is required and, during downward movement of the press head through the charger, air is trapped in the column of tobacco being compressed and the air is compressed as the tobacco is compressed. Because of presence of the compressed air in the compressed cake of tobacco, the press head cannot be returned immediately at the end of its down stroke, else the compressed cake of tobacco will increase in height as soon as the press head moves upwardly. To counter this problem, the prior art approach has been to hold the press head at the bottom of its stroke for a period on the order of fifteen seconds, this being time enough for the compressed air in the cake to escape so that the cake "takes a set". Thus, the trapped air increases the cycle time of the packer by about 15 seconds, a time which constitutes a significant portion of the total cycle.
Various appraches have been adopted in the prior art to reduce packer height. A "two fill" operation has been used, with the charger being shorter than required for the total amount of tobacco for one case or bale, and the press head has been forced down to compress the tobacco of the first fill into the compression chamber and then raised to allow the second fill, then forced down again through a final compression stroke. However, the two fill approach has had the disadvantage of causing a line of demarcation in the final compressed cake, the line of demarcation resulting from the use of the two successive full compression strokes. Being observable to prospective buyers of the packed tobacco, such a line of demarcation is objectionable. Another approach has been to tamp the tobacco in the charger before pressing, usually with a tamping device having downwardly projection "fingers". Though such tamping operations make room for additional tobacco, thus allowing shortening of the charger, they have the disadvantage of causing degradation of the tobacco, particularly the breaking down of the large pieces of lamina into small fragments. There has accordingly been a continuing need for improvement.